Internal-combustion engine



May l5, 1923.

J. DAVIDSON INTERNAL coMBUsTroN ENGINE Filed April 28 1921 2 Sheets-Sheet l ...w @N Lu a oo May l5, 1923. @55,132

.1. DAVIDSON -INTERNAL- COMBUSTION ENGINE Filed April 28 1921 2 Sheets-Sheet 2 Patented May 15, 1923.

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. OFF C i JOHN DAVIDSON, F TUTBURY, BURTON-ON-TRENT, ENGLAND.

INTERNAL-CO1VIBITSTION ENG-INE.

Application filed April 28, 19291. Serial No. 465,214.

(GRANTED UNDER THE PROVISIONS 0F, THE ACT OF MARCH 3, 1921, 41 STAT. L., 1313.)

To all 'whom t may concern.'

Be it known that I, JOHN DAVIDSON, a British subject, residing at The Elms,

Tutbury, Burton-on-Trent, in the county ofl Lancaster, England, have inventedrnew and useful Improvements in Internal-Combustion Engines, of which the following 1s a specification.

This invention relates generally to that type of internal combustion engines which have one or more sets `of working pistons adapted to reciprocate simultaneously in the same direction, each set being connected with a charging piston, andis more particularly applicable to engines such as described in my British specification 119,414 of 1918.

The object of said invention is to build engines of the specified type which vwill run more efficiently than hitherto and torender same .simpler in construction than has hitherto been the case- According to my invention I employfor charging purposes the inner or in the case of vertical engines, the under 'side of the charging piston, instead of the outer or upper side as described in British specilication 119,414 and provide a delivery port or `ports between the inner or under side of the charging cylinder and the working chamber.

I attain this object by the means illustrated in the accompanying two sheets of drawings, in which Figure 1 is a side view of a vertical engine, part of which is in vertical section.

Figure 2 is a detached horizontal section on line 2 2 of Figure 1 and Figure 3 is a detached horizontal section on line 3 3 of Figure 1.

Figure 4, is a front view in vertical section of another vertical engine.

Figure 5 is a part-sectional side view of the same.

Figures 6, 7 and 8 are detached horizontal sections on lines 6 6, 7 7 and 8 8 respec- 45 tively of Figure 4.

Like numerals refer to same throughout the several views.

Referring to Figures 1 to 3 of the drawparts ings, in one constructionin accordance with.

my invention as applied to a vertical` engine, the charging piston 1 has formed with it on the under or inner side a tubular portion 2 to which is attached the connecting rod 3 in the usual way;

'Ihe tubular portion `2 is arranged to work in a guide 4 provided at the lower or inner end of the charging cylinder 5, and consequently the guide 4 and` tubular portion 2 cut off thelower 0r inner endof the charging cylinder 5 `entirely from the crank chamber 6 of the engine.

With a View to preventing unnecessary compression of air taking place,'and at the same time with a view tomaintainingasnear as possible a constant pressure within the crank chamber 6 of the engine,the upper side of the charging pistonl is preferably placed in communication with the crank chamber 6 by suitable means. One suitable means consists'of a port or hole 23 formed in the top 7 of the charging piston in such a manner that communication is effected with the crank chamber 6, through the extended tubular portion 2 on the bottom of the charging piston.

port 8 is provided in the charging cylinder 5 and connected up t0 the fuel supply, for example to a carburetter 8a. This port may be situatedv about half way between the ends of the charging cylinder 5. A port 9 is also provided in the charging cylinder approximately at the bottom thereof. The port 9 is connected by a passage 10 to the inlet chamber 11 containing the inlet ports 12 of the working cylinders 13. Exhaust takes place in the usual manner through the ports 14, whilst cooling water may be circulated by means of theoutlet 16 and inlet 15.

In operation on the upward stroke of the working pistons to compress a charge in the working cylinders, a partial vacuum is produced in the lower part of the charging cylinder with the result that a working charge is drawn into the same when the charging piston has uncovered the port 8.

. On ignition of the compressed charge in the working cylinders 13, the working and charging pistons perform their downward stroke and the working charge drawn into the lower part of the charging cylinder is forced through the port 9 and passage 10 into the chamber 11. On completion of the down stroke; the inlet ports 12 and exhaust ports 1 4` are uncovered bythe wvorking pistons and the charge inthe chamber 11 enters the working cylinders 13. The next up or compression strokenow commences andthe inlet ports 12iare`again` shut olf by the working pistons, whereby a partial vacuum is again produced in the lower part of the charging cylinders and theh'ereinbefore described operations repeat themselves.

It willbe app'reciatedthat asthe coinpression in the charging cylinder takes place in accordance" with"my invention n the downward Ior iiiinerstroke,V the charge is compesse'd at the"right time" for charging.

f-lhefen'gin'e fdescribed" is of the valveless type; the charging piston being of `such a length'tliat itnly'uncovers the port'8' towards the"`end of itsloutwa'rd Aor 'upward strke.

` The I'charging "pump, however, may be fittedi'w'ith a pistonvalve driven from the crank shaft, and as "illustratedby way of example in Figures 4fto' 8 ofthe drawings. This'valvef'erialoles` the charging pump" to work at high'eretciency, b'ut for the smallest size of 'engines "it Imay be dispensed with.

"Ijnftheengine i'llust'ratedin Figures t to 8, thecliargingpistonl has a `tubular 'eXn tension Q working ina tubular guide-*aand connected to. the connecting rodl 3' as 1in the lier'einbefore fdescribed construction.

.A valve casing 17 'is provided connected by afport" 18, "see particularly Figures '5 `and 6, 'tothe lower endof "the charging cylinder 5. inlet 19 is provided for the'entrance of'the'working charge to the 'casing 17,` and the casing is connected by a port20 and `passage Qltol thedi'stributing chamber 11 for theuinletiiports v12of5the. working cylinder13.`f

L piston-valveQQis' reciprocated in the casing 17 for ezianiple by 'means ofl an eccen tric onthe crank shaft'of the engine; the cy'cle offoperations being `asy follows z- `lDuring the'fup or compression stroke of the'engine; the valve22 connects'the-ihlet 19 withthe port 18 anda 'working charge is drawn fbyithe charging piston 1 into-the charging lcylinder through 1 the p'ort 18. During the ydown or working stroke'of' thev pistons-the valve connects-the port18 with the vpassage-'21and' the working charge is forced Vby thef'piston 1 1through theport 18 into' the4x passage y21andv chamber 11; from whence it enters Ethe working cylinders 13 as soon as 'the yworking pistons uncover the inlet ports 12at Athe end Aof their working stroke.

' In Figure 8 holes 23 are shown in Ithe top 7 of the Ycharging piston to connect thefnpper jpistons may beused in connection with one charging puinppiston.

.Y clam 1. In an internal combustion engine of the specified type, "working: cylinders `acrank chamber; a charging cylinder between the working cylindersv'and rthe crank chamber working pistons in the working cylinders a charging piston ini .theichargiing cylinder rigidly connected tot said working! pistons `;ffa tubular extension on said "charging` cylinder a stationary tubular. guide i embracing fsaid extension; port in' thatend ofthecha-rging cylinder which is situated nearestthewcrank chamber .inlet and" .exhaust ports in che workingl lcylinders ;1 4andy passage v)between ther port in; the' charging cylinder and said inlet ports adapted to convey combustible mixtureI from ythe i, said endl/ofthe charging cylinder tofthe working cylinders.

"2. Inan internal combustion'.y ngine ofthe specified type; working cylinders acharging cylinder; charging ypiston therein, a crank case'` connected to fsaidcharg'ing; cylinder ;l a tubular i extension i on saidy charging piston -a stationary tubular guide embracing said extension and cooperating with said extension to cutoff the interiorofthecharging cylinder f from the l crank kcase apport providedinfthe charging cylinder ;-a 4piston valve f controlling' the entrance;A andV exit l of a working charge through saidilport g 'and. a passage connecting said; port tothe working cylinders. d y

3.d In l; an internal combustion engine of thei specified kind, working' cylinders; a charging cylinder forming a continuation; of the working cylinders; workingnpistonsin saidfcylinders; achagging piston/fin said charging` cylinder andrigidlyy connected to said working'UpistonsinV spaced relation thereto; a crank chamber on said charging cylinder; an extensiononithe working piston communicating with the crankcase an open ingin the charging piston connecting'the space betweenfthe iworking pistons and chargingjpiston tothe interior of thev crank case. I

1.111 any internal combustionengine'.of the specifiedtype,yworking cylinders; a charging cylinder; charging vpiston `*therein;a crank case connected'to said lchar'ging cylinder; a tubular extension on saidfcharg-`I ing piston; a stationary. tubularguide` embracing said extension. `and cooperating with said extension to out off the interior `through said port; and av passage connecting said port to the Working cylinders.

Signed at Manchester, in the county of Lancaster, England this 7th day of April= JOHN DAVIDSON. Witnesses ALFRED BossHARDT, MARY IDA BossHARDT. 

